Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/s390/kernel/early_printk.c b/arch/s390/kernel/early_printk.c
index 40c1dfe..6f24d83 100644
--- a/arch/s390/kernel/early_printk.c
+++ b/arch/s390/kernel/early_printk.c
@@ -25,7 +25,7 @@
 	if (early_console)
 		return 0;
 	/* Accept only "earlyprintk" and "earlyprintk=sclp" */
-	if (buf && strncmp(buf, "sclp", 4))
+	if (buf && !str_has_prefix(buf, "sclp"))
 		return 0;
 	if (!sclp.has_linemode && !sclp.has_vt220)
 		return 0;